1. Field Of The Invention
The present invention relates generally to sensors, and more particularly but not exclusively to sensors employed in integrated circuit fabrication.
2. Description Of The Background Art
Fabrication of an integrated circuit (IC) typically requires deposition of one or more layers of material onto a wafer. The deposited material, which is also referred to as xe2x80x9cthin filmxe2x80x9d or simply xe2x80x9cfilmxe2x80x9d, is preferably deposited such that it has uniform thickness across the wafer or localized regions of the wafer. As is well know, the more uniform the film thickness, the better. Thus, a technique for facilitating dispensing of uniform amounts of material on a wafer is generally desirable.
The present invention relates to methods and apparatus for detecting droplet characteristics. Embodiments of the present invention may be used in various applications including, without limitation, in dispensing uniform amounts of materials on a wafer and other workpieces.
In one embodiment, a sensor includes two plates that form a capacitor. A droplet passing between the plates changes the capacitance of the sensor, thereby triggering an amplifier coupled to the sensor to generate an output signal. The output signal is indicative of droplet characteristics and may be used to calibrate a mechanism that dispensed the droplet.
These and other features and advantages of the present invention will be readily apparent to persons of ordinary skill in the art upon reading the entirety of this disclosure, which includes the accompanying drawings and claims.